Lift mechanism for tractors



Sept, 3, 1940.

A. c. LINDGREN El AL LIFT MECHANISM FOR TRACTORS Filed Dec. 27, 193-7 5Sheets-Sheet i MM nz .wG m a Carlwlfott.

A. LINDGREN ET AL LIFT MECHANISM FOR TRACTORS Sept. *3; "1940.

Filed Dec. 27, 1937 5 Sheets-Sheet 2 23 Inventors Sept 3, 1940.

A. C. LINDGREN El AL LIFT MECHANISM FOR 'TRACTORS Filed Dec. 27, 1937 5Shaets-She et 3 OarZ 153 gfrwentore filwazmcjgw P 1940. A. c. LINDGR'EN:1- AL 2,213,401

LIFT MECHANISM FOR TRACTORS Filed Dec. 27, 1937 5 Sheets-Sheet 4Inventory fllavas'aLzlzzd r1912 Carl Zl/MO Sept} 9 A. c. LINDGRIEN ET AL2,213,401

LIFT MECHANISM FOR TRACTO RS Filed Dec; 27, 1937 5 Sheets-Sheet s ls F111. f 68 w- O 7 o o Inveiz tors uikleaaus C. Ltndgren Gajrl ll/lfott.

Patented Sept; 3, 1940 UNITED STATES PATENT OFFICE Rock Falls, 111.,

assignors to International Harvester Company, a corporation of NewJersey Application December'27, 1937, Serial No. 181,778

45 Claims.

This invention relates to hydraulic lift mechanism for lifting andlowering implements directly connected to tractors. An object of theinvention is to provide an improved and simplified form of liftmechanism, which is easily controlled by the operator of the tractor bya single control means.

Another object of the invention is to provide an improved liftingmechanism for tractors having independently mounted implements where itis desired to lift and lower the same in consecutive or er.

In general, the invention comprises a tractor or motor propelledvehicle, on which two implements are mounted at different locations with1 separate fluid expansible means for each of the implements to lift thesame out of its ground engaging position, a pump driven by the motor ofthe vehicle for delivering a fluid to and from a fluid supply casing,and a valve arranged to interrupt this flow of fluid between the pumpand casing, to divert the fluid and deliver the same to the fluidexpansible means to lift the implements. At the time this valve isclosed, liquid is delivered simultaneously to each of the fluidexpansible means and the entire arrangement is so designed that the unitresistance in one of the fluid expansible means is less than .that inthe other. As a'result, one of the implements is lifted prior to liftingof the other implement. When the implements have reached their liftedposition, the valve will open automatically and thereby continue theinterchange of fluid between the pump and the casing, and means willcome into play automatically to hold the implements in their liftedpositions. To lower the implements, means is provided, which isassociated with the control means for operating the valve, whereby theretaining means may be affected in such manner as to lower theimplements in consecutive order.

For other features and a better understanding of the invention,reference may be had to the following description taken in connectionwith the accompanying drawings, in which:

Figure 1 is a side view of a tractor, showing implements and the liftingmechanism of the present invention connected thereto 5 supply casingcontaining the valve arrangements, .with the cover removed and lookingtoward the rear of the tractor;

Figure 3 is a cross-section of a portion of the transmission casing ofthe tractor and showing Figure 2 is a view of the interior of thefluidthe fluid pump and fluid casing in section, looking in the direction ofline 3-3 of Figure 2;

Figure 4 is an elevational view of the rear face of the fluid casing andof the fluid gear pump, which is mounted on the rear of the casing;

Figure 5 is a sectional view of the casing taken on the line 3-3 ofFigure 2, but with-the valve in an open position;

Figure 6 is a similar elevational view taken on the line 3-3 of Figure2, showing the position of the parts when the valve is closed;

Figures 7, 8 and 9 are sectional elevational views taken on the line 1-1of Figure 2, showing the trap valve means for retaining the implementsin their lifted positions at different positions, and the means foraffecting the retainin means to lower the implements;

Figure 10 is a cross-section, also in elevation, of the fluid casing inpart, taken on the line Ill-l0 of Figure 9; v

Figure 11 is a modified form of valve arrangement with the cover of itscasing removed;

Figure 12 is a sectional view of the modified valve and mechanism foroperating the same,

taken along the line I2-I2 of Figure 11; and,

Figure 13 is a sectional view of the trap valve retaining means and itsmeans for affecting the same to lower the implements, taken along theline l3-l3-of Figure 11.

In general, the invention is shown applied to a tractor or motorpropelled implement carrying frame, generally indicated at 2| havingside beam or sills 22, a transmission and final drive housing 23, a rearaxle housing 24, rear wheels 25, and a front steering wheel 26 operatedfrom 35..

an operator's station 2l. At the front of the tractor there areforwardly extending bracket members 28 connected to the forward ends ofthe side sills 22, to which the usual cultivating implements 29 may beattached to extend rearwardly thereof and adapted for vertical movementby pivoting of the usual drag link 3| in a bracket clamp 32 fixed to atransversely extending tool supporting member 33, which in turn iscarried by the bracket members 28. In order to give parallel liftingmovement to the cu1tivator implement 29, there is provided a second link34 pivoted to the upper end'of the bracket clamp 32 and to the implement29. Pivotally mounted on the transverse tool support is a lifting arm35, the upper end of which has connected thereto a lifting link 36connected at its lower end with the implement 29. The lifting arm 35 maythus be pivoted to effect an upward movement of the link 36 for liftingand lowering the implement 29.

Rigidly mounted on the rear axle 24 is a bracket 31, to which a rearimplement 38 is pivotally mounted for movement to and from its groundposition and adapted to be lifted by means of a rockable crank arm 39having the usual lifting link 4 I. A usual pressure link 42, having apressure spring, may also be attached at one end to the bracket 31 forthe purpose of supplying downward pressure to the implement 38.

Mounted on the bracket 31 is an inverted L- bracket 43, extendingupwardly and forwardly of the tractor, on which is pivotally mounted arockable bell-crank member 44, which is connected with the crank member39 by means of an adjustable link 45, adjustable for the purpose ofregulating the working depth of the rear implement 38. Connected to theforward end of the inverted L-shaped bracket member 43, there is a fluidexpansible chamber means 46 having its piston connected to thebell-crank 44 and, in turn, through the above mentioned linkage, toraise and lower the rear implement 38.

Mounted at the upper part of the bracket 43 there is an upstandingcrank-operated pinion means 41 having for operation a rack member 48,that is, in turn, connected to a second expansible chamber means 49,which has its piston connected to a longitudinally movable push-pipe 5|for the operation of the lift arm 35, to lift and lower the frontimplement 29. It should now appear that there are two independentlymounted implements at different locations -on the tractor, each of.which has a separately mounted fluid expansible chamber means forrespectively lifting the same. While only one fluid expansible chamberfor lifting the forward implement is shown, it should be understood thata second fluid expansible chamber means can be used on the opposite sideof the tractor for lifting and lowering the front implement on thatside. This second expansible chamber means may be preferably in fluidcommunication with the same source of fluid supply as the expansiblechamber means 49. For the rear implement only one fluid expansible means46 is necessary, as implements transversely of the tractor may beconnected to the crank 39, that may have other crank arm portionslaterally spaced across the rear of the tractor. Each of the fluidexpansible means are of the single-acting type.

The entire assemblage is so designed, due to the weight of theimplements, the length of the various lever arms, and the size of thepiston within the expansible chamber means-that less unit resistance tothe lifting of the implements is presented to the fluid expansible means48 for the front implement than in the fluid expansible means 46 for therear implement. All of this is purposely arranged and designed to givethis effect, so that, when the different fluid chamber means arepresented with fluid from the same fluid source, the front implementswill be lifted prior to the lifting of the rear implements. Thepresentation of fluid pressure to these elements will be hereinafterdescribed more in detail.

Mounted forwardly of the transmission final drive housing 23 andsupported thereon, there is a fluid supply casing 52, which is shownmore in detail in Figures 2 and 3. The casing 52 is connected at itsrear face to a bracket 54, preferably in the form of a housing, whichis, in turn, connected to the transmission final drive housing 23 andhas a depending rib portion 55 with a foot portion 56 to engage thetransmission final drive housing 23, to give. strength to the brackethousing 54, as shown in Figure 3.

The relationship of gearing within the transmission final drive housingis preferably that shown in the Patent No. 1,982,436 to E. A. Johnston,which has an auxiliary gear 51 adapted to be operated by the motor ofthe motor propelled vehicle. This gear, as described in the patent, isordinarily used for driving a power take-off shaft 58, that extendssubstantially the length of the housing 23 and normally adapted fortaking off power'at the rear of the housing. This same shaft is used inthe present invention for driving a gear pump 59 located within thebracket housing 54. The outlet of this shaft 58 through the forward endof the housing 23 has been modified substantially to provide the shaft58 with a male coupling member 6| threadedly connected thereto and alsoto have an inwardly extending cup member 62 for containing a ballbearing assem 13' 63, which, in cooperation with a ledge portion 64 ofthe cup member 62, keeps the shaft 58 from sliding rearwardly. Thecup-shaped member 62 also has a flange portion 65, which is disposedbetween the housing 23 and the bracket 54 when the latter is attached tothe tractor.

The bracket housing 54, in addition to having a pump contained thereinwith its casing portions 59' and 58", has also a centrally disposeddrive shaft 66 for driving the pump, which, in turn, has a femalecoupling member 61 fixed thereon for engagement with the male coupling6| on the shaft 58 when the bracket 54 and casing 52 are mounted on thetransmission housing 23. In order to prevent excess leakage of oilbetween the transmission housing 23 and bracket housing 54, there areprovided sufficient gaskets 68 around the pump drive shaft 66, and thegaskets 68 between the pump body portion 59" and the bracket housing 54.

The gear pump comprises the usual two gears 1| and 12, the former ofwhich is rotatably mounted on a spindle stud 13 mounted on the rear faceof the fluid casing 52, and the latter of which is fixed to the driveshaft 66 to be driven thereby. Surrounding both of these gears is thepump body portion 59' (Figure 4), shaped to contain an inlet passagemeans 14 and an outlet passage means 15 adapted to cooperaterespectively with holes 16 and 11 in the rear face of the fluid supplycasing 52. The body portion 59" of the pump has a bushing 18 adapted tofit over the drive shaft 68, serving as a cover for one side. 'ofthepump when fixed to the body portion 59' and both secured to the rearface of the housing 52 by means of relatively long bolts 19 adapted tobe screwed into threaded pockets 8| in therear face of the casing 52.

Communicating with the intake passage 14 of the pump and with the holeportion 16 in th face of the casing 52, there is a passage portion 82within the casing 52 (Figure 2), which extends downwardly and opens intothe bottom of the fluid casing for the purpose of supplying fluid to theinlet side of the pump. Means 8 2, taken with the opening 16, thusprovides the fluid communication with the inlet side of the pump. Justbelow the bottom end of this passage 82, there is a stop-cock 63, whichmay be opened for draining of the casing at various times.

Communicating with the hole 11 in the rear face of the casing 52 andwith the outlet side of the pump. there is a horizontally extendingpassage means 84 (Figure 3) to a chamber or fur- 2,218,401 the side ofthe housing Fluid is thus delivered to the passage-way 85 and thencedivided and delivered to the respective passage-ways 86 and 81. Thepassage-way 96 is connected through a fluid connection 88 to the fluidexpansible means 49 for'lifting the front implement. In communicationwith the passage means 81, there is a fluid connection 89 for deliveringfluid to the expansible chamber means 46 for lifting the rear implement.It should thus be seen that a fluid communication is provided fordelivering fluid from the outlet side of the pump to the fluidexpansible lifting chambers 46 and 49.

Also in communication with the passage means 84 there is a port 9|,which is normally open to permit the outward f'ow of fluid from the gearpump back into the su ply chamber within the fluid casing 52. Thispassage 95 and port 9I and the intake passage'82 to the pump thus willnormally permit interchange of 'fluid between the pump 59 and the supplycasing 52. The fluid, in passing through the port 9I, also passesthrough an enlarged passage means 92, in which may be located a ballvalve 93 for closing the port 9|, and a spring 94 (Figure 3) formaintaining a predetermined pressure for providing a spring bias to thevalve 93 upon closing the same by compression of the spring.

When it is desired to raise the implements, this valve 93 is closed bymeans to be hereinafter described. The flow of fluid from the outletside of the pump will thus be diverted to the passage means 85 outwardlyto the fluid expansible means- 46 and 49 to lift the implements. Fluidis supplied at a constant rate, filling up the passage connections andthe fluid expansible chambers, or, in other words, the fluid expansiblechambers are thus in direct communication with the outlet side of thepump 59. Due to the fact that the unit resistance on the fluidexpansible means 49 for the front implement is less than .the unit ofresistance for the fluid expansible means 46 for the rear implement, theexpensible chamber will first be actuated to lift the front implement;and, when filled with fluid, the fluid expansible means 46 will next befilled with fluid to effect lifting of the rear implement. The frontimplement'is thus lifted prior to lifting of the rear implement. Thiseffect is desirable upon reaching the end of a field which is beingcultivated, so that the benefit of cultivating with the rear implementsexactly to the edge of the field will be accomplished. In order toprovide a safety or by-pass, the valve 93 has been purposely arranged tobe spring biased. 'As soon as the rear implement is lifted, the valve 93will tend to by-pass or continue the interchange of fluid between thepump 59 and the casing 52.

To insure positive opening of the valve 93, although the pressur'e biasof the spring 94 would appear sufficient, there has been provided, asshown particularly in Figures 2, 3, 5 and 6, means for automaticallyopening the pressure valve 93 when the implements have reachedtheirlifted position. This means takes the form of a piston 95 in a chambermeans 96, which has communication with the passage means 84. By havingthe means for opening the valve 93 as one which is responsive topressure in the fluid communications, this means will have the functionof positively opening the valve 93 upon any overload which might occurdue to clogging in the open upon clogging just the same as at thecompletion of the lifting of the implements. The automaticopening means,however, does insure a positive, release of the spring 94 from againstthe valve 93, taking the bias from the valve and permitting a greaterflow of fluid through the port 9|.

The means for closing and opening the valve 93 and its association withthe automatic means 95 for opening the same upon overload will now beexplained. The chamber means 96 extends forwardly from the rear of thecasing 52 with an opening at its forward end, which is adapted to beclosed-by a cap or cover member 91, which is fluid communications. Thus,the valve 93 will' bolted to the chamber means 96 by means of bolts 98and has a centrally disposed hole therein through which a stem or pin99, in engagement with the piston 95, may slide. This pin will thusslide and protrude behind the face of the cover member 91, dependingupon the pressure exerted on the piston 95. Surrounding the pin 99 andpressing against the piston 95," there is a spring I9I having apredetermined resiliency. This spring I M tends to hold the pistonseated against the opening with the passage means 94 until pressure inthe passage 84 becomes sufiicient to overcome the same to push the pin99 forwardly through the cover 91.

The chamber means 96 is in vertical alinement with the enlargedpassage-way 92. The cover member 91 on the chamber means 96 has apivoted arm member I92 pivoted thereon, and having a projecting portionI93 adapted to centralize within the spring 94 as the same is pivotedtoward the ball valve 93 to close the same. This arm member I92 is neverpermitted to be out of connection with-the more or less loose spring 94in the passage means 92. When the projected portion I93 is farthest awayfrom the ball valve 93, the spring 94 is released and there will be a.free flow of fluid from the passage means 84 over the spring 94,through the passage means 92, and into the fluid supply chamber withinthe casing 52. Pivoted on the forward part of the arm member I 92 is 'atoggle link I94, which, in turn, is pivoted to an operating arm memberI95 having a portion I96 adapted to be engaged by the piston operatedpin 99 and rigidly connected to a transverse rock-shaft I91 rockablypivoted within the casing and protruding through the casing at one side.The operating arm member I95 is fixed to the transverse rock-shaft I91by a bolt I98 extending through bifurcated portions on the operating armmember I95 and through a washer and key member I99, which extends into akeyway in the shaft to insure a fixed and rigid connection therewith.The transverse shaft I91 is operatedby a manual arm member III fixed tothe same, outside of the casing and -having a handle portion I I2connected thereto and extending longitudinally rearwardly to a locabreakthe toggle by pulling the operating handle tion near the operator'sstation 21 on the ve- H2 rearwardly, the implements will lift to theirfull height and then the toggle will be broken by pressure of the pin 99on the portion I06 of the operating arm I05. Due to the force with whichthe toggle mechanism is kicked out, there is a tendency for the armmember I05 to return to the position shown in Figure 3, but this isundesirable for reasons to be explained later.

Now that the implements have been raised, some sort of means must beemployed to retain the implements in their raised position. Such adevice might take the form of a mechanical contrivance, but may alsotake a form utilizing the return pressure of thefluid caused by theweight of the implements tending to rgfurn to their ground engagingposition. In eacli'of the passage chambers 86 and 81 are disposed,respectively, one-way trap valves H3 and H4 (Figures 7 to 10). In orderto prevent these ball valves from sticking in the ends of the passagepipes 88 and 89 in their vertical movement as fluid is being passed bythem to lift the implements, there is provided above them a loose pieceof metal H5.

When the implements are lifted and the valve 93 has opened, the tendencyof the fluid in the fluid expansible means is to return to the fluidsupply casing 82. This action is prevented by the trap valves H3 and H4.The implements are thus held in their lifted position by a column offluid pressing against the valves H3 and H4. These ball or trap valv'esmay thus be termed means for retaining implements in their liftedpositions.

In order to lower the implements, some sort of means must be used toeffect the opening of valves H3 and.II4 and, in accordance with thespirit of this invention, to effect lowering of one implement prior tolowering of the other implement. A separate means for opening each valveis used. Under each ball valve is located a respective pin H6 and H1slidable in a portion of the casing 52 to contact the ball valves II3 toraise the same against pressure due to the weight of the implements onthe column of the fluid and to permit return of the fluid first from thepipe 88 of the front implement, and then from the pipe 89 of the rearimplement. For accomplishing this effect there is provided a platemember H8 located underneath the pins H6 and H1 and supported in thecasingby portions H9 and I2I of the wall of the casing, yet permittingmovement thereof upwardly to lift the pins H8 and I" for opening theirrespective ball valves. lift the pin H8 and then the pin 1, there is acam member I22 pivoted to the inside of the casing by a screw bolt I23,and adapted to retate either on the threads or with the threads of thebolt, (Figure 10), and having thereon a radially extending portion I24adapted to engage the plate H8, upon the cam member I22 being rotated ina clockwise direction, nearv to the pin H6 (Figure 8). Associated withthe plate H8 at a point near to engagement of the pin II'I therewith isa spring member I that tends to hold that end of the plate H8 down whilethe cam is operating to lift the opposite side of the plate H8. Afterthe cam member and portion I24 have been rotated to the position shownin Figure 8, there can still be further rotation of the same to overcomethe spring pressure of the spring I25 to effect a final lifting of theplate H8 to lift the pin II! to the transverse shaft I81.

To cause the plate H8 to first and effect lowering of the rearimplement, as in the position shown in Figure 9.

To operate the cam I22 about its pivot bolt I23, there is a connectinglink I26 that pivotally connects with a second arm member I21 fixed Thisconnecting link is pivotally connected to the cam member at I28. Byhaving this cam member or means for effecting lowering of the implementsconnected to the same transverse shaft I01, to which is also connectedthe operating means for the valve 93, simplicity of construction andsingularity of control is accomplished. The means for effecting theimplement retaining means may thus be controlled by the same handlemeans H2. To effect lowering of the implements, the handle means H2 ispulled rearwardly by the operator, and in the opposite direction whenthe valve 93 is to be closed to lift the implements. Due to the pressureon the ball valves, a noticeable amount of resistance is felt by theoperator in the handle means H2 when attempting to pull the handle meansrearwardly to effect first the lowering of the front implement. Afterthe front implement is lowered, a second resistance is felt in thehandle means H2, which must be overcome to lower the rear implement.This is in effect an indication to the operator as to the position ofthis implement as the mechanism is being operated. This is a positiveeffect, much the equivalent of the effect obtained by an operator of anautomobile in shifting transmission gears. The position of the operatingarm member I85 is that shown in Figure 3, when the last implement hasbeen lowered and-the handle means I I2 has been pulled rearwardly as faras it can go.

The operating mechanism for the valve 93, as stated above, kicks overits center position with considerable force, and, if it were not delayedor retarded, that force would be suflicient to cause the arm member I05to return to the position shown in Figure 3, and thus cause immediatelowering of the implements. This movement would causev the shaft I81 tomove just as though the operator were pulling on the handle means I I2to effect the retaining trap valves for lowering the implements. Toovercome this tendency, there is provided a dash-pot I29 located in thecover I3I for the forward part of the casing 52. This dash-pot isconnected with arm I21 by a link I32, so that force imparted to theshaft I81 will be transmitted to a piston I33 in the dash-pot I29 andconnected to the lower end of the connecting link- I32. This dash-potwill permit the arm member I05 to move only to the position shown inFigure 5. When the control handle H2 is pulled rearwardly, the armmember I05 will first take a. position somewhere between that positionshown in Figure 5 and that shown in Figure 3 to lower the frontimplement,

and then it will be finally moved to the position shown in Figure 3. Thepull of the control handle H2 rearwardly would also be opposed by thedash-pot as well as by the column pressure on the trap valves. Thedash-pot will get its medium of operation from the supply casing, thefluid used in the casing being preferably oil, or some light liquid.

The casing 52 may be filled from time to time as necessary, by removinga plug 90 from one of the discharge pipes 88 or 89, Figure 4. To providea vent while the casing is being replenished with liquid, there is astop-cock I34 communicating with the interior of the casing.

If it is desired to operate the front implement on only one side of thetractor at a time, the front implement may be held in its liftedposition by a flop-over latch I35 mounted on the fluid expansiblechamber means 49, so that it will engage the end 5 la of the push pipe5| when the same is pushed forward by the fluid expansible means 49.This will in no way affect the fluid system, and the front implement onthe other side of the tractor can be operated the same as before. Thestem of the piston in the fluid expansible means 49 extends into thepipe and abuts a plug and bolt indicated at 5Ib.

The form of the invention shown in Figures 11, 12 and 13 functionsgenerally the same as the form shown in Figures 1 to 10. It has a casingI36, which is very similar to the casing 52 of the other form, but moresimple in construction. The pump, similar to that shown in Figure 3, isarranged on a rear face the same as in. the other form. Forcommunication to the intake of the pump from the bottom of the casingthere is a passage pipe I31 connected with the inlet side of the pump atI38. The fluid from the outlet side of the pump passes in through therear face of the casing I36 to a passage means I39 extendingtransversely within the wall of the rear face of the casing to the sidethereof in communication with a longitudinally extending passage I4I(Figure 13), and thence upwardly to vertically extending passageways I42and I43 for delivering fluid to the respective fluid expansible meansfor the front and rear implements. These vertical passages contain,respectively, trap valves I44 and I45.

Leading from the passage I39, there is a port I46 and a forwardlyextending passage chamber I41, through which the fluid may flow when avalve I48, which may engage the port I46, is out of engagement with thesame. When the pump is operating, there will thus be an interchange offluid between the pump and the fluid casing I36. The fluid will leavethe fluid casing I36 through the passage means I31, into the pumpthrough the port I38, and return from the pump through the-passage I39and port I46. When it is desired to lift the front and rear implements,

the valve I48 will be made to close the port I46, whereby fluid will bediverted and caused to flow vertically through the vertical chambers I42and I43 to their respective fluid expansible means. For the same reasonsstated in connection with the other form of the invention, the frontimplement will be lifted prior to lifting of the rear implement. Theentire assembly is so designed that the unit resistance on the fluidexpansible means 49 for the front implement is less than the unitresistance presented to the fluid expansible means 46 for the rearimplement.

For operating the valve I 48, there is provided an operating arm memberI49, that is fixed to afransverse shaft I5I extending through the casingI36 at one side thereof, where the manual control means II I and itshandle H2 is attached. The arm memberl49. has a recess I52 arranged withits opening coinciding with the passage chamber I41. This recess is forthe reception of a bolt member I53 and a spring I54. This spring I54 ispreloaded by tightening of a nut I55 on the'front side of the operatingarm I49.

When the hand control H2 is pushed forwardly by the operator, the headof the bolt I53 will engage the valve I48 and the spring I54 will becompressed until a face I49 surrounding the recess I52 engages with theend of the passage means I41. The valve I48 is thus closed,

butfree to open automatically when the pressure becomes too great in thefluid passages, as when the final implement has been lifted. When thisoverload is reached, the valve I48, in permitting passage of fluid, willvibrate quite considerably, giving indication to the operator that heshould release pressure from the control means. Thus, the function ofthe spring I54 is very similar to the function of the spring 94described above in connection with the other form of the invention. Theyboth serve to place their respective valves under a pressure bias.

When it is desired to preload the spring I 54 to a greater amount, awasher I56 is disposed in the recess I52, and. the nut I55 is tightened,so that the clearance between the face I49 and the end I41 of thepassage means I41 is the same as before. In this way, the spring IE4 isshortened and its resistance to force, due to the shortening of thesame, will be greaterthan before. Thus, when the operator moves theoperating arm I 49 toward the ball valve I48 to engage the faces I49 andI 41', a greater pressure will be presented to the ball valve I48. Thus,there has been provided a means of. adjusting for the pressure of thefluid required to automatically open the ball valve I48. The use of thewasher I56 is the only way that this adjustment may be made, since it isdesired to maintain the same clearance between the face I49 and the faceI 41. Instead of a washer I56, the adjustment might be effected by athreaded collar.

The operating arm' member I49 has a laterally extending portion I49"(Figure 11), on which is mounted a roller I 51 extending to a point invertical alinement with the ball valves I44 and I45. ThlS roller I51will take a path of movement under the ball valve in the form of an arewhen the transverse shaft I5I and operating member I 49 are rocked.Cooperating with this roller is a cam plate member I58 having a camsurface I 58' thereon for engagement with the roller and on which aresupported valve open-' ing pins I59 and NH adapted to cooperaterespectively with the ball valves I44 and I45.

After the implements have been raised, there will be pressure on theball valves I 44 and I45, so that the implements will be retained intheir lifted position. As the roller I51 is moved in a[counter-clockwise direction as viewed in Figure 12, the ball valve I 44will first be lifted to efiect lowering of the front implement, theplate member 58 being maintained at its portion underneath the ballvalve I 45 by a spring I62 against.

a ledge portion I63 on the wall of the casing I36. A further movement ofthe roller on the cam surface I 58 will thus be required to overcome thespring I62 to effect opening of the ball valve It should now be apparentthat a very similar control means is used for closing the ball valve toeffect lifting of the implements and also for effecting opening of-theballvalves I44 and I45, to that disclosed in the previous form of theinvention. Both means are fixed to a single hand and foot controllocated near the operator's station 21.

Instead of there being a toggle mechanism for opening the valve inaddition to its biasing spring. 94, the arrangements as to the principaloperation are practically identical. The toggle mechanism of the priorform can be opened by hand, if desired, the same as the valve closingmeans of will be effected.

the present form may be opened upon release of pressure from its controlhandle.

Sometimes the operator desires to have the implements loweredimmediately after lifting them to their flifted position, or onlypartially. This can be done automatically in the present form by the useof a coil spring I64 surrounding the transverse operating shaft l5!connected to the operating member I49 and to the casing I36, and socoiled that, when the operator applies pressure to close the ball valveI48, a spring pressure is built up in the same, so that, upon a quickrelease of the control handle by the operator, the force will cause theoperating member I49 and cam I51 to return sufficiently to engage thecam plate I58 and thereby effect immediate lowering of the implements.

It should now be seen that the foregoing description provides anefficient fluid operated lifting and lowering mechanism for tractormounted implements in which a consecutive lifting and lowering of theimplements may be effected, and

one in which this lifting and lowering may be done by a single controlmeans located near the operators station on the tractor.

While various other forms of construction may be used, such changes inform would be deemed to be included within the spirit and scope of thepresent invention as defined by the appended claims.

What is claimed is:

1. In combination, an implement-carrying frame, implements independentlymounted for movement on said frame, a fluid expansible means for eachimplement to respectively move the same, means for simultaneouslysupplying fluid to the expansible means, the fluid expansible means forone of the implements being presented with less unit resistance than thefluid expansible means of another implement, whereby consecutivemovement of the respective implements will be effected.

2. In combination, a motor propelled vehicle,

-implements independently mounted for movement on the vehicle, a fluidexpansible means for each implement to respectively move the same, meansfor simultaneously supplying fluid to the expansible means operated bythe motor, the fluid expansible means for one of the implements beingpresented with less unit resistance than the fluid expansible means ofanother implement whereby consecutive movement of the respectiveimplements will be effected.

3. In combination, a motor propelled vehicle having auxiliary gearingoperated by the motor, an implement mounted for movement at one locationon the vehicle, a second implement independently mounted for movement atanother location on the .vehicle, a fluid expansible means for eachimplement to respectively move the same, means for simultaneouslysupplying fluid 'to the expansible means adapted to be operated by theauxiliary gearing, the fluid expansible means for one of the implementsbeing presented with less unit resistance than the fluid expansiblemeans of the second implement, whereby consecutive'movement of therespective'implements 4. In combination, an implement carrying frame,implements independently mountedto be lifted and lowered on the frame, afluid expansible means for each implement to lift the same, means forsimultaneously supplying fluid to the different expansible'means, thefluid expansible means for one of the implements being presented 5. Incombination, a motor propelled vehicle having auxiliary gearing operatedby the motor, implements independently mounted on the vehicle to belifted and lowered, a fluid expansible means for each implement to liftthe respective implements, a fluid pump connected to said gearing,passage means from said pump to the different expansible means fordelivering fluid thereto, the fluid expansible means for one of theimplements being presented with less unit resistance than the fluidexpansible means of another implement, to effect consecutive lift ofimplements, and valve means in the different passage means to retain thefluid in the expansible means when the implements have been lifted, andmeans for opening the different valve means to lower the implements.

6. In combination, an implement-carrying frame, implements mounted onthe frame to be lifted and lowered, a fluid expansible means for eachimplement to lift the respective implements, means for simultaneouslysupplying fluid to the different expansible means, valve meansassociated with the supply means to the separate expansible means forautomatically retaining the fluid in said expansible means when theimplements have been lifted, and a single manual control means foropening said valve means in consecutive order to effect subsequentlowering of the respective implements.

7. In combination, a motor propelled vehicle having auxiliary gearingoperated by the motor, an implement mounted on the vehicle to be liftedand lowered, a fluid pump adapted to be connected for operation to saidgearing having a fluid inlet passage means and a fluid outlet passagemeans, a fluid supply casing having separate passage means connectingrespectively the inlet and outlet of the pump to permit normalinterchange of fluid therebetween, a pressure biased valve in thepassage connecting the outlet passage of the pump, a fluid expansiblemeans to lift the implement, passage means for connecting the expansiblemeans with the outlet passage of the pump, and means operable at thewill of the operator of the vehicle for closing said pressure biasedvalve to divert the flow of fluid from the pump to the passage means ofthe expansible means connecting with the outlet of the pump to lift theimplement, said pressure biased valve being adapted to openautomatically due to fluid pressure at the completion of the lift of theimplement to continue the interchange of fluid be tween the pump and thecasing.

8. In combination, a motor propelled vehicle having auxiliary gearingoperated by the motor,

an implement mounted on the vehicle to be lifted passage of the pump,and means operable at the will of the operator of the vehicle forclosing said pressure biased valve to divert the flow of fluid from thepump to the passage means of the expansible means connecting with theoutlet of the pump to lift the implement, said pressure biased valvebeing adapted to open automatically due to fluid pressure at thecompletion of the lift of the implement to continue the interchange offluid between the pump and the casing, means for retaining the implementin its lifted position, and means for operating said retaining means topermit lowering of the implement.

9. In combination, a motor propelled vehicle having auxiliary gearingoperated by the motor, an implement mounted on the vehicle to be liftedand lowered, a fluid pump adapted tobe con-.

nected for operation to said gearing having a fluid inlet passage meansand a fluid outlet passage means, a fluid supply casing having separatepassage means connecting respectively the inlet and outlet of the pumpto permitnormal interchange of fluild therebetween, a pressurebiasedlvalve in the passage connecting the outlet passage of the pump, afluid expansible means to lift the implement, passage means forconnecting the expansible means with the outlet passage of the pump, andmeans operable at the will of the operator of the vehicle for closingsaid pressure biased valve to divert the flow of fluid from the pump tothe passage means of the expansible means connecting the outlet of thepump to lift the implement, said pressure biased valve being adapted toopen automatically due to fluid pressure at the completion of the liftof the implement to continue the interchange of liquid between the pumpand the casing, means for retaining the implement in its liftedposition, means for operating said retaining means to permit lowering ofthe implement, and a single control means common to both of said valveclosing means and saidlast mentioned means.

10.,In combination, a motor propelled vehicle, an implement mounted onthe vehicle to be lifted and lowered, a fluid pump operated by saidmotor and having an inlet side and an outlet side, a fluid supplycasing, separate fluid communications between the casing and therespective inlet and outlet sides of the pump to permit interchange offluid therebetween, a fluid expansible means to lift the implement incommunication with the outlet side of the pump, a valve in thecommunication between the casing and the outlet side of the pump, togglemechanism for operating said valve, means for operating said togglemechanism to operate the valve, and means for automatically upsettingthe toggle mechanism to open the valve at the end of the lifting of theimplement resulting from the closing of said valve and of the divertingof fluid to the fluid expansible means.

11. In combination, a motor propelled vehicle,

an implement mounted on the vehicle to be lifted and lowered, a fluidpump operated bysaid motor and having an inlet side and an outlet side,a fluid supply casing, separate fluid communications between the casingand the respective inlet and outlet sides of the pump to permitinterchange of fluid therebetween, a fluid expansible means to lift theimplement in communication with the outlet side of the pump, a valve inthe communicationbetween the casing and the outlet side of the pump,toggle mechanism for operating said valve, means for operating saidtoggle mechanism to operate the valve,

means for automatically upsetting the toggle mechanism to open the valveat the end of the lifting of the implement resulting from the closing ofsaid valve and of the diverting of fluid to the fluid expansible means,means for retaining the implement in its lifted position, and means foroperating said retaining means to lower the implement.

12. In eombinr tion, a motor propelled vehicle, an implement mounted onthe vehicle to be lifted and lowered, a fluid pump operated by saidmotor and having an inlet side and an outlet side, a fluid supplycasing, separate fluid communications between the casing and therespective inlet and outlet sides of the pump to permit interchange offluid therebetween, a fluid expansible means to lift the implement incommunication with the outlet side of the pump, a valve in thecommunication between the casing and the outlet side of the pump, togglemechanism for operating said valve, means for operating said togglemechanism to operate the valve, means for automatically upsetting thetoggle mechanism to open the valve at the end of the lifting of theimplement resulting from the closing of said valve and of thedivertingof fluid to the fluid expansible means, means for retaining theimplement in its lifted position, means for operating said retainingmeans to lower the implement, control means common to both of said meansfor operating the toggle mechanism and the means for operating saidretaining means in which movement in one direction thereof operates toset the toggle mechanism and close said valve without actuation of theoperating means,

and means for prohibiting actuation of the op-- erating means by virtueof the upsetting force of the toggle mechanism upon opening of the valveand return movement of the control means.

13. In combination, a motor propelled vehicle, implements independentlymounted for movement on said vehicle, a fluid pump adapted to beoperated by said motor, a fluid supply casing, fluid passage meansbetween said pump and casing to normally permit interchange of fluidtherebetween, a fluid expansible means for each implement to lift thesame in communication with one of the fluid passages between the pumpand easing, a valve in one of said passages, the

closing of which causes fluid to be diverted to the expansible means forlifting the implements, means for operating said valve, separate meansfor retaining each of the implements in their lifted position, and meansfor operating the retaining means to lower the implements at differenttimes, the same being operable manually in separate steps to lower firstone implement and then another.

14. In combination, a motor propelled vehicle, implements independentlymounted for movement on said vehicle, a fluid pump adapted to beoperated by said motor, a fluid supply casing, fluid passage meansbetween said pump and casing to normally permit interchange of fluidtherebetween, a fluid expansiblemeans for each implement to lift thesame in communication with one of the fluid passages between the pumpand easing, a valve in one of said passages, the

closing of which causes fluid to be diverted to the expansible means forlifting the implements, means for operating said valve, separate meansforretaining each of .the implements in its lifted position, means foroperating the retaining means to lower the implements at differenttimes, and

- to permit interchange said operating means adapted to be operated bythe means for operating the valve.

15. In combination, a motor propelled vehicle, an implement mounted onthe vehicle to be lifted and lowered, a fluid pump operated by saidmotor and having an inlet side and an outlet side, a fluid supplyingcasing, fluid communication between the casing and the sides of the pumpto permit interchange of fluid therebetween, a fluid expansible means tolift the implement in fluid communication with the outlet side of thepump,-

a valve adapted to close one of the fluid communications to divert thefluid to the fluid expansible means, operating means for closing saidvalve comprising a pre-loaded spring means adapted to place the valveunder spring pressure, but being so loaded as to permit the valve toautomatically open to continue the interchange of fluid between the pumpand the casing at the completion of the lifting of the implement.

16. In combination, a motor propelled vehicle, an implement mounted onthe vehicle to be lifted and lowered, a fluid pump operated by saidmotor and having an inlet side and an outlet side, a fluid supplycasing, fluid communication between the casing and the sides of the pumpof fluid therebetween, a fluid expansible means to lift the implement influid communication with the outlet side of the pump, a valve adapted toclose one of the fluid communications to divert the fluid to the fluidexpansible means, operating means for closing said valve comprising apre-loaded spring means adapted to place the valve under springpressure, but being so loaded as to permit the valve to automaticallyopen to continue the interchange of fluid between the pump and thecasing at the completion of the lifting of the implement, and meanswhereby the loading of said spring may be adjusted.

17. In combination, a motor propelled vehicle, an implement mounted onthe vehicle to be lifted and lowered, a fluid pump operated by saidmotor and having a inlet side and an outlet side, a fluid supply casing,fluid communications between the casing and the sides of the pump topermit interchange of fluid therebetween, a fluid expansible means tolift the implement in fluid communication with the outlet side of thepump, a valve adapted to close one of the fluid communications to divertthe fluid to the fluid expansible means, manual means for closing saidvalve to lift the implement, means for retaining said implement in itslifted position, means associated with said manual means for operatingthe retaining means to lower the implement, and spring means associatedwith said manual means tending to resist the closing movement thereof toeffect quick return movement of said manual means upon release of thesame to automatically operate said operating means of the retainingmeans.

18. In combination, a tractor having forward and rear portions, animplement mounted for vertical movement on the forward portion of thetractor, another implement mounted for vertical movement on the rearportion of the tractor; a fluid expansible means for each implement torespectively move the same, means for simultaneously supplying fluid tothe fluid expansible means, the fluid expansible means for the implement mounted on the forward portion being presented with less unitresistance than the fluid expansible means for the implement mounted onthe rear portion, whereby consecutive movement to divert the flow of ofthe implements on the front and rear portions will be respectivelyeffected.

19. In combination, a tractor having forward and rear portions, animplement mounted on the forward portion of the tractor to be lifted andlowered, another implement mounted on the rear portion of the tractor tofluid expansible means for each implement to lift the same, means forsupplying fluid to the fluid expansible means, the fluid expansiblemeans for the implement mounted on the forward portion being presentedwith less unit resistance than the fluid expansible means for theimplement mounted on the rear portion, means for discharging the fluidfrom the different fluid expansible means in consecutive order to effectlowering of the implement on the forward portion prior to lowering ofthe implement on the rear portion, whereby consecutive lifting andlowering of the implements of the respective forward and rear portionwill be effected.

20. In combination, an implement-carrying frame, an implement mountedfor movement on said frame, pump means for supplying fluid underpressure having a fluid inlet passage means and a fluid outlet passagemeans, a fluid supply casing having separate passage meansconnectingrespectively the inlet and outlet passage means to permitnormal interchange of fluid therebetween, a pressure biased valve in theoutlet passage means, a fluid expansible means to lift the implement,passage means for connecting the expansible means with the outletpassage means, and means for closing the pressure biased valve fluidfrom the pump means to the passage means of the expansible means to liftthe implement, said pressure biased valve being adapted to openautomatically due to excess fluid pressure to continue the interchangeof fluid between the pump means and the casing.

21. In combination, an implement-carrying frame, an implement mountedfor movement on said frame, a fluid pressure pump having an inlet sideand an outlet side, a fluid supply easing, fluid communication betweenthe casing and the sides of the pump to permit interchange of fluidtherebetween, a fluid expansible means to lift the implement incommunication with the outlet side of the pump, a valve adapted to closeone of the fluid communications to divert the fluid to the fluidexpansible means, means for closing said valve including a pre-loadedspring means adapted to place the valve under spring pressure but beingso loaded as to permit the valve to automatically open upon beingsubjected to excess pressure to continue the interchange of fluidbetween the pump and the casing.

22. In combination, a frame, a source of fluid supply, a means includingan implement and a fluid expansible means for connecting the same to thesource of fluid supply, a second means including an implement and a belifted and lowered, a

fluid expansible means for connecting the same to the same expansiblemeans for connecting the same to the fluid supply, a second meansincluding an implement adapted to be mountetd for movement on the rearportion of the tractor and having a fluid expansible means forconnecting the same to the fluidsupply, and both of the means beingconstructed so thereof is effected prior to any movement of the othermeans with the implement frame on the rear portion upon the operation ofthe fluid supply means.

24. In combination, a plurality of implements,

' a fluid expansible means for each implement to effect operation of thesame, means for simultaneously supplying fluid to the expansible means,the fluid expansible means for one of the implements being presentedwith less unit resistance than the fluid expansible means of anotherimplement, whereby consecutive operation of the respective implementswill be effected.

25. In combination, a motor propelled vehicle,

a plurality of implements connected to the vehicle, a fluid expansivemeans for each implement to'effect operation of the same, means forsimultaneously supplying fluid to the expansible means operated by themotor, the fluid expansible means for one of the implements beingpresented with less unit resistance than the fluid expansible means ofanother implement, whereby consecutive operation of the respectiveimplements will be effected.

26. In combination, a plurality of implements, a fluid expansible meansfor each implement to effect operation of the same, means forsimultaneously supplying fluid to the different expansible means, thefluid expansible means for one of the implements being presented withless unit resistance than the fluid expansible means of anotherimplement, and means for separately discharging the fluid of thedifferent expansible means at different times, whereby consecutiveoperation and discharging of the fluid expansible means will beeffected.

2'7. In combination, a plurality of implements, a fluid expansible meansfor each implement to effect the operation of the same, means forsimultaneously supplying fluid to the different expansible means, avalve means associated with each of the separate expansible means foreffecting discharge of the fluid therefrom, and a single manual controlmeans for operating the respective valve means in consecutive order toeffect consecutive discharging of the respective fluid expansible means.

28. In combination, a plurality of implements, a single-acting fluidexpansible means for each implement to effect operation of the same,means for effecting consecutive'operation of the respective fluidexpansible means from one position to another position, means foreffecting consecutive discharge of the fluid from the respectiveexpansible means to operate the implement to return the same to the oneposition, and a single manual control means for operating both of saideffecting means, the said control means being operable in separate stepsto returnfirst the one implement and then the other implement.

29. In combination, a motor propelled vehicle, implements mounted on thevehicle to be lifted and lowered, a single-acting fluid expansible meansfor each implement to lift the same,'means for effecting consecutiveoperation of the respective fluid expansible means and consequentlifting of the respective implements, and means for effectingconsecutive discharge of the fluid from that movement of the implement.

the respective expansible means to thereby effect consecutive loweringof the respective implements, the said last mentioned effecting meansbeing operable manually in separate steps to lower first one implementand then the other implement.

30. In combination, a motor propelled vehicle, implements mounted on thevehicle to be lifted and lowered, a single-acting fluid expansible meansfor each implement to lift the same, means for effecting consecutiveoperation of the respective fluid expansible means and consequentlifting of the respective implements, means for effecting consecutivedischarge of the fluid from the respective expansible means to therebyeffect consecutive lowering of the respective implements, and a singlemanual control means for operating both of said effecting means, thesaid control means being operable in separate steps to lower first oneimplement and then the other implement. Y

31. In combination, an implement carrying frame, a plurality ofimplements mounted on.

said frame to be lifted and lowered, a singleacting fluid expansiblemeans for each implement to effect operation of the same, means forsimultaneously supplying fluid to the respective expansible means, thefluid expansible means for one of the implements being presented withless unit resistance than the fluid expansible means of anotherimplement to thereby effect consecutive lifting of the implements, andmeans for effecting consecutive discharge of the fluid from therespective expansible means to thereby effect consecutive lowering ofthe respective implements.

32. In combination, an implement carrying frame, a plurality ofimplements mounted on said frame to be lifted and lowered, asingle-acting fluid expansible means for each implement to effectoperation of the same, means for simultaneously supplying fluid to therespective expansible means, the fluid expansible means for one of theimplements being presented with less unit resistance than the fluidexpansible means' of another implement to thereby effect consecutivelifting of the implements, means for effecting consecutive discharge ofthe fluid from the respective expansible means to thereby effectconsecutive lowering of the respective implements,

and a single manual control means for operating both the supplying meansand the discharge effective means.

33. In combination, a frame, a plurality of implements connected to theframe, a single-acting fluid expansible means for each implement toeffect operation of the same, a fluid supply means delivering fluid tothe respective fluid expansible means, a one-way trap valve for eachfluid expansible means for normally permitting flow of fluid to thesame, and a single control means for opening the respective trap valvesin consecutive order to effect consecutive operation of the implements.

34. In combination, an implement-carrying frame, a plurality ofimplements mounted on the frame to be lifted and lowered, asingle-acting fluid expansible means for each implement to lift thesame, a fluid-supply means for delivering fluid to the respective fluidexpansible means, a one- Way trap valve foreach fluid expansible meansfor normally permitting flow of fluid to the same, and a single controlmeans for opening the respective trap valves in consecutive order toeffect consecutive lowering of the respective implements.

35. In combination, an implement-carrying frame, a plurality ofimplements mounted on said frame to be lifted and lowered, asingle-acting fluid expansible means for each implement to lift thesame, a fluid supply means for delivering fluid to the respective fluidexpansible means, a one-way trap valve for each expansible means fornormally permitting flow of fluid to the same, and a single controlmeans for opening the trap valves in consecutive and delayed order whilemoving the same through definite intervals of space in one direction tothereby effect delayed lowering of the respective implements.

36. In combination, a frame, an implement connected to the frame, afluid expansible means for operating the implement with respect to theframe, a fluid supply means for delivering fluid to the expansible meansincluding a valve adapted to be closed by manual means to divertdelivery of fluid to the fluid expansible means, and said valve beingadapted to open automatically due to fluid pressure set up in the supplymeans at the completion of the operation of the expansible means.

37. In combination, a frame, an implement connected to the frame, afluid expansible means for operating the implement with respect to theframe, a fluid supply means for delivering fluid to the expansible meansincluding a valve adapted to be closed by manual means to divertdelivery of fluid to the fluid expansible means, said valve beingadapted to open automatically due to fluid pressure set up in the supplymeans at the completion of the operation of the expansible means, meansfor retaining the implement in its new position after the valve has beenopened, and means for operating said retaining means to permit furtheroperation of the implement.-

38. In combination, a frame, an implement connected to the same, a fluidexpansible means for operating the implement with respect to the frame,a fluid supply means for delivering fluid to the expansible meansincluding a valve adapted to be closed by manual means to divertdelivery of fluid to the fluid expansible means, said valve beingadapted to open automatically due to fluid pressure set up in the supplymeans at the completion of the operation of the expansible means, meansfor retaining the implement in its new position after the valve has beenopened, means for operating said retaining means to permit furtheroperation of the implement, and a single manual control means common toboth said pressure biased valve and said last mentioned operating means.

39. In combination, an implement adapted for operation from one positionto another, a fluid expansible means for operating the implement, afluid supply means for delivering fluid to the expansible meansincluding a valve adapted to be closed by manual means to divertdelivery of fluid to the fluid expansible means, toggle mechanism foroperating said valve, manual control means for setting said toggle meansand to close said valve, and means for automatically upsetting thetoggle mechanism at the end of the operation of the implement.

40. In combination, an implement adapted for operation from one positionto another, a fluid expansible means for operating the implement, afluid supply means for delivering fluid to the expansible meansincluding a valve adapted to be closed by manual means to divertdelivery of same, said valve means including a pre-loaded fluid to thefluid expansible means, toggle mechanism for operating said valve,manual control means for setting said toggle means and to close saidvalve, means for automatically upsetting the toggle mechanism at theendof the operation of the implement, means for retaining the implementin its new position, and means for operating the retaining means toeflect return of the implement to its original position.

41. In combination, an implement adapted for 1Q operation from oneposition to another, a fluid expansible means for operating theimplement,

a fluid supply means for delivering fluid to the expansible meansincluding a valve adapted to be closed by manual means to divertdelivery 15 of fluid to the fluid expansible means, toggle mechanism foroperating said valve, manual con- ,trol means for setting said togglemechanism and to close said valve, means for automatically upsettingsaid toggle mechanism at the end of the Zn operation of the implement,means for retaining the implement in its new position, means foroperating the retaining means to effect return of the implement to itsoriginal position associated with said manual control means for settingthe g5 toggle mechanism, and means for prohibiting actuation of thisoperating means due to the upsetting force of the toggle mechanism.

42. In combination, a plurality of implements, each of which is adaptedfor operation from one 39 position to another, a separate fluidexpansible means for operating each implement, fluid supply means fordelivering fluid to the respective fluid expansible means including avalve for controlling the flow of fluid to the expansible means, meansfor operating said valve to effect operation of the respectiveexpansible means, separate means for each implement to retain the samein the new position, and manual means for operating each of theretaining means at different times and in separate steps to efiectconsecutive return of the implements to their original positions.

43. In combination, an implement adapted for operation, a fluidexpansible means for operating the implement, a fluid supply means fordelivering fluid to the fluid expansible means including a valve meansfor controlling the flow of fluid to the fluid expansible means andadapted to be closed to effect operation of the spring means adapted toplace the valve under 50 predetermined spring pressure but being loadedso as to permit the valve to automatically open at a predetermined fluidpressure within the fluid supply means to thereby cause cessation of theoperation of the fluid expansible means.

44. In combination, an implement adapted for operation, a fluidexpansible means for operating the implement, a fluid supply means fordelivering fluid to the fluid expansible means including a valve meansfor controlling the flow of fluid to the fluid expansible means andadapted to be closed to effect operation of the same, said valve meansincluding a pre-loaded spring means adapted to place the valve underpredetermined spring pressure but being loaded so as to permit the valveautomatically to open at a predetermined fluid pressure within the fluidsupply means to thereby cause cessation of the operation of the fluidexpansible means, and means whereby the loading of said spring means maybe adjusted.

45. In combination, an implement adapted for operation, a fluidexpansible means for operating the implement, a fluid supply means fordeliver- 75 ing fluid to the fluid expansible means including a valvemeans for controlling the flow of fluid to the fluid expansible meansand adapted to be closed to effect operation of the same, manual meansfor closing the valve to operate the implement, means for retaining, theimplement in. its operated. position, means associated with the manualmeans for operating the retaining means to permit return of theimplement to itsoriginal position, and spring means associated with themanual means tending to resist the closing movement thereof tooptionally efiect quick return movement of said manualmeans upon releaseof the same to automatically 5 operate said operating means of theretaining means;

ALEXUS C. LINDGREN. CARL W. MO'IT.

